same situation the last time I drove my car, I changed plugs and set the at 0.8 gap, had injector cleaner run through it, changed oil and it still idled rough sometimes normal sometimes low, confusing the heck out of me, however I did find I had a boost leak but its been stripped since and not driven it, will be putting it back together soon and changing the fuel pump, fuel filter, dizzy cap kit, and full belt kit. Fingers crossed one of them sorts it.